Insulating conduits and high-voltage insulators with integrated conductors, optical fibers in particular, are known in a variety of embodiments. European Patent No. 0 265 737 describes such an arrangement, where an optical fiber is wound in a spiral along an optical fiber carrier, the latter of which is in turn designed as an insulating wind located in a an cavity of a high-voltage insulator.
Another arrangement is described in U.S. Pat. No. 3,485,940, where an optical fiber is surrounded by a polyester tube which passes through a core of a insulator in a longitudinal direction.
European Patent No. 0 146 845 describes another high-voltage insulator, where a light guide is carried longitudinally through the insulator in a groove in an intermediate layer arranged between a core and shielding elements.
With the high-voltage insulators described below, the optical fiber is usually pulled subsequently into the prefabricated insulator or insulating conduit. German Patent No. 27 55 734 describes the use of longitudinal grooves forming channels to accommodate the optical fibers with these channels then being closed. Similarly, it is described in French Patent No. 0 2 725 302 that a groove in the form of a spiral can be provided in the wall of the insulator, and a continuous extruded ribbon of elastomer can be introduced into this groove. Then a optical fiber is placed on a top side of this ribbon and then the optical fiber and the ribbon are compressed, e.g., by rolling, to insert the ribbon into a bottom of the groove and embed it in the elastomer material.
German Patent No. 29 01 872 describes the use of an optical fiber in an intermediate layer running in a longitudinal direction, and exiting from this intermediate layer through holes.
German Patent No. 39 21 442 also describes the use of empty cables for subsequent insertion of optical fibers having an insertion aid for subsequent insertion of these optical fibers.
A conventional method of producing high-voltage insulators is by winding insulating conduits made of epoxy resinates with a laminate structure of glass fibers or synthetic fibers. Such insulating conduits are known from the brochure "MR-Isolierrohre ROTAFIL.RTM. fur die Hochspannungstechnik" (MR-ROTAFIL.RTM. Insulating Conduits for High Voltage Technology), imprint VK23-0/88de. In these winding methods, it is not readily possible to wind empty conduits, because it results in air-filled gaps at a side of the wound empty conduit having a negative effect on dielectric and electrical properties.